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libfdt: Add and use a node iteration helper function.

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This patch adds an fdt_next_node() function which can be used to
iterate through nodes of the tree while keeping track of depth.  This
function is used to simplify the iteration code in a lot of other
functions, and is also exported for use by library users.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
David Gibson 2008-02-12 11:58:31 +11:00 committed by Jon Loeliger
parent 202863e4dd
commit fc9769ac2b
3 changed files with 131 additions and 174 deletions
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41
libfdt/fdt.c
View file

@ -129,6 +129,47 @@ uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
return tag;
}
int fdt_next_node(const void *fdt, int offset, int *depth)
{
int nextoffset = 0;
uint32_t tag;
if (offset >= 0) {
tag = fdt_next_tag(fdt, offset, &nextoffset);
if (tag != FDT_BEGIN_NODE)
return -FDT_ERR_BADOFFSET;
}
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_PROP:
case FDT_NOP:
break;
case FDT_BEGIN_NODE:
if (depth)
(*depth)++;
break;
case FDT_END_NODE:
if (depth)
(*depth)--;
break;
case FDT_END:
return -FDT_ERR_NOTFOUND;
default:
return -FDT_ERR_BADSTRUCTURE;
}
} while (tag != FDT_BEGIN_NODE);
return offset;
}
const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
{
int len = strlen(s) + 1;

258
libfdt/fdt_ro.c
View file

@ -65,7 +65,7 @@
static int nodename_eq(const void *fdt, int offset,
const char *s, int len)
{
const char *p = fdt_offset_ptr(fdt, offset, len+1);
const char *p = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, len+1);
if (! p)
/* short match */
@ -104,50 +104,24 @@ int fdt_num_mem_rsv(const void *fdt)
return i;
}
int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
int fdt_subnode_offset_namelen(const void *fdt, int offset,
const char *name, int namelen)
{
int level = 0;
uint32_t tag;
int offset, nextoffset;
int depth;
CHECK_HEADER(fdt);
tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
if (tag != FDT_BEGIN_NODE)
return -FDT_ERR_BADOFFSET;
for (depth = 0;
offset >= 0;
offset = fdt_next_node(fdt, offset, &depth)) {
if (depth < 0)
return -FDT_ERR_NOTFOUND;
else if ((depth == 1)
&& nodename_eq(fdt, offset, name, namelen))
return offset;
}
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_END:
return -FDT_ERR_TRUNCATED;
case FDT_BEGIN_NODE:
level++;
if (level != 1)
continue;
if (nodename_eq(fdt, offset+FDT_TAGSIZE, name, namelen))
/* Found it! */
return offset;
break;
case FDT_END_NODE:
level--;
break;
case FDT_PROP:
case FDT_NOP:
break;
default:
return -FDT_ERR_BADSTRUCTURE;
}
} while (level >= 0);
return -FDT_ERR_NOTFOUND;
return offset; /* error */
}
int fdt_subnode_offset(const void *fdt, int parentoffset,
@ -307,76 +281,61 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
{
uint32_t tag;
int p = 0, overflow = 0;
int offset, nextoffset, namelen;
int pdepth = 0, p = 0;
int offset, depth, namelen;
const char *name;
CHECK_HEADER(fdt);
tag = fdt_next_tag(fdt, 0, &nextoffset);
if (tag != FDT_BEGIN_NODE)
return -FDT_ERR_BADSTRUCTURE;
if (buflen < 2)
return -FDT_ERR_NOSPACE;
buf[0] = '/';
p = 1;
while (nextoffset <= nodeoffset) {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_END:
return -FDT_ERR_BADOFFSET;
for (offset = 0, depth = 0;
(offset >= 0) && (offset <= nodeoffset);
offset = fdt_next_node(fdt, offset, &depth)) {
if (pdepth < depth)
continue; /* overflowed buffer */
case FDT_BEGIN_NODE:
name = fdt_get_name(fdt, offset, &namelen);
if (!name)
return namelen;
if (overflow || ((p + namelen + 1) > buflen)) {
overflow++;
break;
}
while (pdepth > depth) {
do {
p--;
} while (buf[p-1] != '/');
pdepth--;
}
name = fdt_get_name(fdt, offset, &namelen);
if (!name)
return namelen;
if ((p + namelen + 1) <= buflen) {
memcpy(buf + p, name, namelen);
p += namelen;
buf[p++] = '/';
break;
pdepth++;
}
case FDT_END_NODE:
if (overflow) {
overflow--;
break;
}
do {
if (offset == nodeoffset) {
if (pdepth < (depth + 1))
return -FDT_ERR_NOSPACE;
if (p > 1) /* special case so that root path is "/", not "" */
p--;
} while (buf[p-1] != '/');
break;
case FDT_PROP:
case FDT_NOP:
break;
default:
return -FDT_ERR_BADSTRUCTURE;
buf[p] = '\0';
return p;
}
}
if (overflow)
return -FDT_ERR_NOSPACE;
if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
return -FDT_ERR_BADOFFSET;
else if (offset == -FDT_ERR_BADOFFSET)
return -FDT_ERR_BADSTRUCTURE;
if (p > 1) /* special case so that root path is "/", not "" */
p--;
buf[p] = '\0';
return p;
return offset; /* error from fdt_next_node() */
}
int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
int supernodedepth, int *nodedepth)
{
int level = -1;
uint32_t tag;
int offset, nextoffset = 0;
int offset, depth;
int supernodeoffset = -FDT_ERR_INTERNAL;
CHECK_HEADER(fdt);
@ -384,38 +343,29 @@ int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
if (supernodedepth < 0)
return -FDT_ERR_NOTFOUND;
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_END:
return -FDT_ERR_BADOFFSET;
for (offset = 0, depth = 0;
(offset >= 0) && (offset <= nodeoffset);
offset = fdt_next_node(fdt, offset, &depth)) {
if (depth == supernodedepth)
supernodeoffset = offset;
case FDT_BEGIN_NODE:
level++;
if (level == supernodedepth)
supernodeoffset = offset;
break;
if (offset == nodeoffset) {
if (nodedepth)
*nodedepth = depth;
case FDT_END_NODE:
level--;
break;
case FDT_PROP:
case FDT_NOP:
break;
default:
return -FDT_ERR_BADSTRUCTURE;
if (supernodedepth > depth)
return -FDT_ERR_NOTFOUND;
else
return supernodeoffset;
}
} while (offset < nodeoffset);
}
if (nodedepth)
*nodedepth = level;
if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
return -FDT_ERR_BADOFFSET;
else if (offset == -FDT_ERR_BADOFFSET)
return -FDT_ERR_BADSTRUCTURE;
if (supernodedepth > level)
return -FDT_ERR_NOTFOUND;
return supernodeoffset;
return offset; /* error from fdt_next_node() */
}
int fdt_node_depth(const void *fdt, int nodeoffset)
@ -443,51 +393,27 @@ int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
const char *propname,
const void *propval, int proplen)
{
uint32_t tag;
int offset, nextoffset;
int offset;
const void *val;
int len;
CHECK_HEADER(fdt);
if (startoffset >= 0) {
tag = fdt_next_tag(fdt, startoffset, &nextoffset);
if (tag != FDT_BEGIN_NODE)
return -FDT_ERR_BADOFFSET;
} else {
nextoffset = 0;
}
/* FIXME: The algorithm here is pretty horrible: we scan each
* property of a node in fdt_getprop(), then if that didn't
* find what we want, we scan over them again making our way
* to the next node. Still it's the easiest to implement
* approach; performance can come later. */
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
for (offset = fdt_next_node(fdt, startoffset, NULL);
offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
val = fdt_getprop(fdt, offset, propname, &len);
if (val && (len == proplen)
&& (memcmp(val, propval, len) == 0))
return offset;
}
switch (tag) {
case FDT_BEGIN_NODE:
val = fdt_getprop(fdt, offset, propname, &len);
if (val
&& (len == proplen)
&& (memcmp(val, propval, len) == 0))
return offset;
break;
case FDT_PROP:
case FDT_END:
case FDT_END_NODE:
case FDT_NOP:
break;
default:
return -FDT_ERR_BADSTRUCTURE;
}
} while (tag != FDT_END);
return -FDT_ERR_NOTFOUND;
return offset; /* error from fdt_next_node() */
}
int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
@ -553,31 +479,15 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
* that didn't find what we want, we scan over them again
* making our way to the next node. Still it's the easiest to
* implement approach; performance can come later. */
do {
offset = nextoffset;
tag = fdt_next_tag(fdt, offset, &nextoffset);
for (offset = fdt_next_node(fdt, startoffset, NULL);
offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
err = fdt_node_check_compatible(fdt, offset, compatible);
if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
return err;
else if (err == 0)
return offset;
}
switch (tag) {
case FDT_BEGIN_NODE:
err = fdt_node_check_compatible(fdt, offset,
compatible);
if ((err < 0)
&& (err != -FDT_ERR_NOTFOUND))
return err;
else if (err == 0)
return offset;
break;
case FDT_PROP:
case FDT_END:
case FDT_END_NODE:
case FDT_NOP:
break;
default:
return -FDT_ERR_BADSTRUCTURE;
}
} while (tag != FDT_END);
return -FDT_ERR_NOTFOUND;
return offset; /* error from fdt_next_node() */
}

6
libfdt/libfdt.h
View file

@ -130,6 +130,12 @@ static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
/**********************************************************************/
/* Traversal functions */
/**********************************************************************/
int fdt_next_node(const void *fdt, int offset, int *depth);
/**********************************************************************/
/* General functions */
/**********************************************************************/